What would happen if a PCV on a car doesn't work?

for my 86 Starion 2.6L turbo/intercooled (stock), im having a problem with deceleration smoke. when hitting boost at any psi, once letting off the gas the car will pour smoke outta the rear end exhaust. its sorta bluish, i lose oil yet my antifreeze is fine, not losing any or any signs of oil in it. only in gear deceleration, no smoke in neutral no matter the rpms....i heard it could be the PCV, how do i check if it is? what are the symptoms pf a bad PCV? how do u know if its bad? i know it should be connected to the valve cover yet i can't find mine...any help? Thanks